(P15-002-25) An Obesogenic Diet With Pulse Does Not Decrease Liver Fatty Acid Content and Improve Insulin Resistance in Mice

Objectives: Healthy dietary pattern plays an important role in obesity prevention. Dry edible bean (Phaseolus vulgaris L.) is considered a healthy diet component and is the most widely produced and consumed pulse crop around the world. This study investigated whether incorporation of whole or milled dried pulses to a high-fat diet affects blood glucose, insulin levels, homeostatic model assessment for insulin resistance (HOMA-IR), and liver fatty acids in mice. We hypothesized that inclusion of pulses into a high-fat diet decreases HOMA-IR and leads to a reduction in fatty liver in mice.

Methods: Male C57BL/6 mice at 4-week-old were randomly assigned to four treatment groups (n=22-24/group) and one of the following diets ad libitum for 12 weeks: a normal-fat (NF; 4.1 kcal/g and 16% energy as fat), a high-fat diet (HF; 4.9 kcal/g and 48% energy as fat), or a HF diet containing either whole beans (HFWB) or milled bean flour (HFMB) at 15% w/w. Diets containing beans were formulated to have similar total energy, protein, and fiber content as the HF diet without beans.

Results: Blood cholesterol, HDL, and HOMA-IR were higher (P < 0.0001) and triglyceride was lower (P < 0.0001) in mice fed the HF diets compared to those fed the NF diet. Mice fed the HF diets had greater liver triglyceride (P < 0.0001) than those fed the NF. Pooled HF with bean groups had greater blood glucose, insulin, and homeostatic model assessment for insulin resistance than the HF diet alone. Milled bean flour had greater impact on blood glucose, insulin, homeostatic model assessment for insulin resistance than whole bean relative to the HF alone. The HF diets increased the content of total liver fatty acids compared to the NF diet. Incorporation of beans into the HF diets did not affect majority of fatty acid content in liver except increasing 22:6n-3 and total n3.

Conclusions: These data indicate that incorporation of pulse into a high-fat diet without reducing total dietary fat content does not reduce liver fat content and improve insulin resistance in mice.

Funding Sources: USDA Agricultural Research Services 3062-10700-002-000D